Espeletia restricta (Millerieae, Asteraceae), a new species from the páramos of northern Colombia
Author
Alzate, Fernando
Group of botanical studies-HUA Herbarium, Institute of Biology, University of Antioquia, Medellín, Colombia.
Author
Giraldo, Sebastián
Group of botanical studies-HUA Herbarium, Institute of Biology, University of Antioquia, Medellín, Colombia.
text
Phytotaxa
2020
2020-02-20
433
4
288
294
http://dx.doi.org/10.11646/phytotaxa.433.4.4
journal article
10.11646/phytotaxa.433.4.4
1179-3163
13875127
Espeletia restricta
Alzate & Giraldo
,
sp. nov
.
(
Figs 1
,
2
).
Type:
—
COLOMBIA
.
Antioquia
:
Municipio Sonsón
,
Vereda La Paloma
, páramo
de Sonsón
,
Cerro de Las Palomas
,
3370 m
a.s.l.
,
5°43’34” N
,
75°14’58” W
,
7 January 2016
(fl),
F. Alzate
5220
(
holotype
: HUA! [2 sheets];
isotypes
:
MO
!, COL!)
.
Espeletia restricta
is a herb with a stem up to
1.2 m
tall, yellowish indument (grayish in
E. occidentalis
), laminae 24–40 ×
6–12 cm
; synflorescences
23–50 cm
long, 0.8–1.2(–1.5) times longer than the rosettes, bracts very variable in number and phyllotaxy; ray florets 31–42, disc florets 110–153.
Caulirosulous
herbs with a stem usually not exceeding
0.6 m
tall but on occasions up to
1.2 m
, not ramified, erect, densely covered by marcescent leaves; stem diameter at rosette base
5–12 cm
. Rosette
0.30–0.42 m
tall and
0.32–0.53 m
in diameter, appearance yellowish.
Leaves
29–43 cm
long, alternate, simple, sessile. Laminae
24–40 cm
×
6–12 cm
, elliptic to oblong, symmetrical, gradually narrowing toward base, base truncate and obtuse, width at lamina base (0.7–)1.4(–3) cm, apex acute, apex shape usually straight but sometimes slightly acuminate, margins entire and slightly revolute. Blades coriaceous, flexible in all stages of development, adaxially rugulate, venular reticulum conspicuous, depressed; abaxially the midvein prominent, longitudinally striated, secondary nerves
6–15 mm
apart, noticeably prominent, excurrently attached to the costa, regularly spaced in the center of the laminae and frequently becoming closer toward base and apex, deviation angle slightly uniform or increasing upwards, varying between 17°–44°, brochidodromous, occasionally weakly anastomosed with each other near the margin, intersecondary veins strongly developed when present, usually one per intercostal area, longer than the half of subjacent-secondary longitude, course proximally and distally parallel to main secondaries, tertiary nerves irregularly reticulated, forming a raised, tiny network with quaternary and quinary nerves, both of which are regularly polygonal reticulated; epimedial tertiaries reticulated and exterior tertiaries course variable, often ending at the margin. Areolation well developed, areoles of relatively consistent size and shape, minutely pilose on the inside. Marginal ultimate venation looped. Freely ending veinlets not visible.
Sheaths
2.7–5.9 cm
× 2.0–
4.1 cm
, multinerved, ovate, apex obtuse, adaxially glabrous, greenbrown, abaxially the indument dense.
Synflorescences
thyrsoid, usually 3–4(–7) coetaneous,
23–50 cm
long, 0.8–1.2(– 1.5) times longer than the rosettes. Synflorescence’s main axe
5–13 mm
in diameter above base, erect, basally rigid, distally flexible; proximal part 0.39–0.87 of total length, with a very variable number (0–8) and phyllotaxy of bracts, those being sometimes 1–3 pairs decussate, other times being 1 opposite basal pair followed by 1–6 alternate bracts or 2 basal decussate pairs followed by 1–4 alternate bracts, even in some cases all the bracts alternate and occasionally without bracts. Bracts, when present,
15–23.3 cm
×
2.1–4.5 cm
, oblong attenuate towards the base, with somewhat connate sheaths, apex acute, the lowermost ones at
0–8 cm
above the base of the synflorescence, the following ones gradually decreasing upwards. Distal part of the synflorescence with 4–14 capitula, the most distal branch usually with 3 but sometimes with 1–2 capitula. Indument on axes and branches yellowish, dense, lanate, longer and less entangled in main axes, bracts with indument similar to leaves.
Capitula
20–27 mm
in diameter, radiate, usually erect, involucre subglobose, each capitulum with 143–186 flowers; ligular circle
25–33 mm
in diameter and disc
15–20 mm
in diameter. Phyllaries becoming smaller inwards and giving the appearance of being distributed in 2–3 whorls, but actually spirally arranged; the external sterile ones usually 4–5, coriaceous, a basal opposite pair of them differentiated for being longer, triangular and with a markedly acuminate apex, meanwhile the remaining ones have acute or slightly rounded apex; the internal fertile ones 3–10, chartaceous, discontinuous, apex acute to rounded. Receptacles convex, glabrous, paleate.
Ray florets
31–42; corollas true ray, yellow; tubes 1.2–2.0 mm long, densely pilose; limbs 7.2–9.9 ×
2.5–3.6 mm
, oblong to elliptic, apically 2–3-lobed, 7–10-veined. Style
4.5–5.9 mm
long, stigmatic branches
2.5–4.6 mm
long.
Achenes
3.7–4.2 mm
×
1.6–2.8 mm
, obconic, triangular in transversal section, usually 3(–6)-ribbed, dark brown when mature.
Pappus
absent.
Disc florets
110–153; corollas tubular yellow, throats
5–5.3 mm
long, mostly glabrous, lobes 5, triangular, tubes
2.1–2.7 mm
long.
Anthers
2.8–3.9 mm
long, apical appendage about 1/8 of anther lengths, rounded. Style
8–9 mm
long, stigmatic branches
0.4–0.5 mm
long, broadening distally, papillose; rudimentary ovary present.
Pappus
absent.
Paleae
7.0–8.7 ×
2.5–3.3 mm
, elliptic, scarious, rigid, basally enclosing florets, usually 7-veined with veins occasionally ramifying dicotomically at medial-distal section, apex acute.
Indument description:
—
Leaves
with indument thickly and densely lanate throughout, adaxially yellowish, forming a uniform cover, with the long trichomes straight to undulated, appressed and not so entangled. The costa abaxially sericeous, yellowish, the rest of the lamina with whitish and entangled trichomes.
Sheaths
abaxially with a dense indument, trichomes long, barbate, undulated, ascending, whitish.
Ray florets
densely pilose, trichomes glandular, multicellular, ascending or patent.
Disc florets
with few external minute trichomes in the tube portion.
Paleae
pubescent apically, on edges and abaxially, mostly over veins, glabrous adaxially.
Etymology:
—The name refers to the extreme level of endemism in the distribution of this taxon.
Morphological affinities:
—
Espeletia restricta
is similar to
Espeletia occidentalis
subsp.
antioquiensis
(
Cuatrecasas 1942: 24
)
Cuatrecasas (2013: 216)
because both have a short stem, no more than
1.5 m
, similar number of capitula per synflorescence (4–14) and distributed in the north of the Central Cordillera.
Espeletia restricta
differs by the size of its synflorescences relative to the rosette length (less than 1.5 times longer than the rosette vs. 2–3 times longer than the rosette), indument colour (yellowish vs. greenish-white) and synflorescences total length (<
50 cm
vs.>
60 cm
).
Taxonomic affinities:
—
Cuatrecasas
et al.
(2013)
proposed a taxonomical affinity for the
Espeletia
species
occurring in the Western Cordillera of
Colombia
. These authors suggested that
E. frontinoensis
Cuatrecasas (1977: 15)
is sister to
E. praefrontina
Cuatrecasas (1980: 10)
, both species endemic of the Western Cordillera. The last two species form a clade that also would include
E. hartwegiana
and
E. pycnophylla
, species with a wider distribution.As a basal group to this clade,
Cuatrecasas
et al.
(2013)
proposed
E. occidentalis
subsp.
antioquensis
. In the same work, the authors suggested that
E. occidentalis
subsp.
antioquensis
is related to
E. grandiflora
Humboldt & Bonpland (1808: 11)
which occurs at the Eastern Cordillera.
Espeletia restricta
is distributed at the same Cordillera as
E. occidentalis
and both have the morphological traits that suggest their taxonomic affinity.
Distribution, habitat and ecology:
—The new species have been collected only in two areas of the páramo of Sonsón, Department of
Antioquia
in the northern Andes Cordillera. Although the total area of the páramo is 8707 ha,
E. restricta
only grows in an area of approximately 2 ha, at elevations between 3300 and
3363 m
a.s.l. The habitat of
E. rectricta
has a vegetation characterized by a very dense and diverse páramo flora, dominated by representatives of
Asteraceae
,
Bromeliaceae
and
Poaceae
families. The dominant vegetation corresponds to shrublands with abundant small plants of the genera
Cortaderia
,
Guzmania, Paepalanthus
and
Disterigma
.
The Sonsón páramo complex is located in the Central Cordillera of
Colombia
, southern department of
Antioquia
and northern department of
Caldas
(
Alzate
et al
. 2016
). The mountain topography of this region allows to have scarce páramo zones, most of the time isolated from one another (
Alzate
et al.
2016
).
Espeletia restricta
populations are found in the southern part of the Central Cordillera of Department of
Antioquia
, while other species of
Espeletia
growing in the nearest area of this Cordillera are separated by a depression formed due to Porce river canyon.
Conservation status:
—This new species has a very restricted distribution and the populations have a low number of individuals, which makes it very susceptible to any environmental change, such as those generated by climate change and anthropic activities. Considering these conditions, it is evident that
E. restricta
is under a very high risk of extinction, since the possible area of occupation of the species would be reduced in a scenario of global warming. Using the occurrence data and based on the assessment carried out on GeoCat, the species was found Critically Endangered (CR) for both IUCN metrics, the extent of occurrence (EOO) and the area of occupancy (AOO).
Additional specimens examined:
—
COLOMBIA
.
Antioquia
:
Municipio Sonsón
,
Vereda La Paloma
, páramo
de Sonsón
,
Cerro de Las Palomas
,
3370 m
.a.s.l,
5°43’34” N
,
75°14’58” W
,
7 October 2011
(fr),
F. Alzate
,
O. Díaz
,
S. Varela
,
P. Pérez
&
S. Murillo
4234
(HUA)
;
Municipio Sonsón
,
Vereda San Francisco
, páramo
de Sonsón
,
Cerro de Las Palomas
, alrededores de la escuela para subir a la cima del cerro,
3250 m
.a.s.l,
5°43’32” N
,
75°15’00” W
,
16 June 2012
(fl),
O. Díaz
,
S. Varela
,
P. Pérez
&
M. Hincapié
861
(HUA)
;
Municipio Sonsón
,
Vereda La Paloma
, páramo
de Sonsón
,
Cerro de Las Palomas
,
3370 m
.a.s.l,
5°43’34” N
,
75°14’58” W
,
16 October 2009
(fr),
F. Alzate
,
A. Álvarez
,
J.P. Naranjo
,
J. Marín
,
N. Montaño
,
S. López
,
A. Diez
,
S. Monsalve
,
W. Berti
,
S. Villa
&
E. Ospina
3337
(HUA)
.